Ore concentration



E; W, WILKINSON. ORE CONCENTRATION.

APPLICATION FILED 056.81 1918.

1,3939% Y Patented Dec. 6,1921.

, Y HIHHHIHIIHHIIIlllllllli s'rarasrarnr re ns.

HITOFT WRAY WILKINSON, OF SAN FNCISCO, QALIFOIRNIA, ASSIGlQ'OR TO MINERALS SETARATION NORTHv AMERICAN COR-PQBATIQN, OF NEW YORK, N. Y. A. CORPORATION 035" MARYLAND. vi

' v .oitn cononn'rna'rrom.

specification of Letters Patent. Patented Dec. 8, 1921.,

'- Application filed December e1, 1918. Serial It"... seems.

T 0 all whom it may concern:

Be it known that l,- EL'ior'r WRAY W11.- KINSON, a subject of the Kingof Great Britain, and resident of the city of San Francisco, county of San Francisco, and State of California, have invented certain new and useful Improvements in Ore Concentration, of which the following is a specification.

My invention relates to processes for concentrating ores or similar substances wherein, or uponthe grinding of which, there are mixtures of solid substances having different physicalpro erties, .by utilizing these difierences. and t e property possemedby certain agents of forming a froth with water or other liquid, the bubbles composing which have the ability of selecting-the solid substances of one or more of the different classes and rejecting the remainder.

-the useful properties of the mineral-frothing agent, thesolid substances to .be sepa:

rated, and the gaseous bubbles.

I have found that by oxidizing mineralfrothing agents, such as the insoluble or oily mineral-frothing agents oleic acid or cottonseed oil, by the agency of heat, a more eflicient mineral-frothing agent is produced. The oxidation of the mineral-frothing agent is carried out by bringing it, either in the form of streams, globules, drops, spray,

- vapor or gas, together with oxygen or air,

' into a heated zone or region.

the products of the oxidation are subjected,

Thereafter to condensation by methods already known. The condensation yields oily liquid, aqueous liquid and uncondensed gas or vapor. Each of the products is a mineral --frothing agent,--one may, however, be more effective Y as such than the others. Again the proportions'of these products vary with different temperatures and with .difielent roper I tions of oxygen, and the temperature and the proportion of oxygen used depends on the nature of the material treated and the nature andqua-ntity ofth'e particular product desired. I

I shall now part cularly describe examples of the carrying out of. my invention with referenre to the accompanying drawings,

which illustrate forms ofapparatus that may be used in carrying out my invention, and shall thereafter point out my invention in claims. Flgure 1 1s -a-d1agrammatic view of an apparatus for the treatmentof frothing prises a copper cylinder permanently closed at the bottom and having a lid f bolted to a flange at the top. The small tube 5 from the gas meter (1 has a regulatingwalve s therein and enters the retort through an opening in the-lid f and terminates near the top of the retort. The material to be treated is supplied to the retort through a burette d from which a tube e extends down through the lid 7 and terminates near the bottom of theretort. A thermo-couple g is arranged in the retort near the bottom thereof and is connected by wires passing through the lid 7 to a voltmeter h, the thermocouple and voltmeter constituting a pyrometer for indicating the temperature maintained at the lower part of the retort.- A tube in extends from the top of the retort through the lid. and carries oil the products. Ali of these tubes and wires make tight joints with the lid. The tube 76 connects with acondenser Z consisting of a coil tube 6 immersed in a water jacket. The condenser coil is connected at its other end by a tube j to three condensing vessels m mi, m arranged in series, the tube j being the inlet tube of the first vessel and extending to near the bottom thereof. An outlet tu e 2' for the or stored for use, atmosphere.

' y of ore.

of the oily condensed product obtained in the tubes m 073. and W per ton (of 2000 lbs.) of

tends from near the top thereof and enters-- and extends to near the bottom of the third vessel m, and an, outlet tube 3' p for the vessel. m extends out near the top thereof and enters the final condensing vessel or l'b The condensing vessels as, m m, are immersed in a water bath in the vessel T- for cooling them. The final con denser or scrubber n conveys the residual products in an upward direction through absorbent material such as absorbent cotton; From this scrubber a tube it passes .to'an air pump 0, and from the outlet pipe 39 of the air pump the residual material in gaseous form is discharged from the treatment system and may b fed directly to the flotation machine, or allowed to escapeto the The following is an example of the carrying out of this invention with oleic acid of the kind known onthe marketas B'akers oleic acid. 250 cc. of this oleic acid are poured into the burette d and the retort is heated so that thepyrometer records a temperature of1000 Fahr. .The stop cock on the burette is then opened so that about 3 cc. of oil per minute flows into the retort, and thereupon the fiow of air is started by the operation of the pump '0 at the rate-of about 0.98 liters per minute. the heated zone is maintained at about 1000 F. White fumes .form and are condensed by the system above described, the condensed material being an oily condensed liquid and an aqueous condensed liquid. The air pump 0 exhausts an uncondensed remainder, which was found to be a good frothing agent.

A pulp was made of 500 grams of zinc ore fronithe Elm Orlu mine, Butte, Montana, ground to pass through a mesh Tyler standard screen, and this was mixed with 1700 cc. of cold tap water. A pulp was made up in a slide machine and acidified with 18.1 pounds of sulfuric acid per ton (of-2000 lbs.) To this pulp was added 1.7 pounds ore, and the whole was agitated at a speed of about 1600 R. P. M. for two minutes. An

excellent froth rose to the top of the pulp,

and after settling of the slimes, was removed. Water was added to make up the proper volume, and the pulp was again agitated'for two minutes at the same speed. The slimes were settled as before, and the froth re moved. Further water was added to make up the proper volume, and the pulp was.

removed.

These three froths were combined, weighed The temperature of were weighed and assayed as tailings, with the following metallurgical results:

i I Percenta e Products. Weight ig of total zinc.

Heads 100. 00 14. 8 0.0 Concentrates. 39. 43 35.0 93. 4 Tailmgs. 60. 57 1. 6 6.6

In carrying out this invention in the apparatus above described with cottonseed oil which like oleic acid is a fatty acid-bearing substance, the cottonseed oil used wasobtained from Eimer and Amend, New York.

The retort was heated so that the pyrometer recorded a temperature of about 1000 Fahrenheit. The stop cock on the burette was then opened so that 4 cc. per minute, or 3.7- grams per minute of the cottonseed oil flowed intothe retort. Thereupon' a fiowof air I and assayed as concentrates, and the residues was started by the operation of the; pump firstat'the rate of 9.6 liters per minute. The temperature as indicated by\ the pyrometer was maintained at about 104:8 F. during the operation. White fumes formed in the apparatus and were condensed in thesystem described. A condensed oily liquid and a condensed aqueous liquid was obtained, and uncondensed gas or vapor was delivered at the pump outlet pipe 32.

The oily condensed products so obtained were of a dark browncolor and partially solid at 60- F, being fluid at about 130 F. The uncondensed products exhausted from the air pump 0 had a strong, unpleasant, 'acrid smell, and werevery lacrymal; The proportions in which the different condensed products were obtained were as follows The first condensation obtained in the tubes m ,-m m contained 56% by volume of the original cottonseed oil used, of which 28% was oily and 28% aqueous.

The second condensation obtained by compressing and blowing air through the absorbent cotton in the scrubber a measured in the operation. 1

There were thus produced 30.5% by volume of oily material and 28.0% of aqueous, making a total of 58.5%, by volume, of con densed products.

Both oily'condensed products 2.5% by volume of thecottonseedoil used were found to give excellent results when used as frothreeaeeo the subaeration type with 1.6 pounds per ton of the first condensed oily product produced by the above reaction.

Agitation was continued for twenty min: utes and a good self-discharging froth was taken off continuously during this time, while air was admitted to the bottom of the flotation machine.

The concentrates were weighed and as sayed, as werethe tailings, with the following result Percentage 1 Products. Weight 53? of total zinc.

Heads..'... 100.0 9.64 100.0 Concentrates 21. 9 38. 48 77. 6 Tailings l. 78.1 2. 67 22. 4

I Another test was made with-exactly the same flotation conditions as above, with the solid particles. in the ore pulp so. as to produce mineral-bearing froth, and separating the froth.

2. The process of concentrating ores which consists in mixing with an ore pulp a mineral .70 frothing agent obtained by subjecting an insoluble frothing agent to partial decom- 'eral frothing agent, obtained by subjecting oleic acid to partial decomposition .in the exception that in place of the condensed'oilyproducts the uncondensed gaseous exhaust from the air'pump -0 was fed into the pulp directly for two minutes, being followed by twenty minutes agitation with the admission of air alone at the bottom of the with the following result:

W ht Assays. P t

e1 ercen age Products. 5 total Zn Zn. insol.

Heads 100.0 14.5 160.0

Concentrates 34. 5 43. 4 21. 7 100.0

failings v 65.5 Trace. Trace.

Ordinary commercial operations with retreatments of the concentrates would in each instance produce -a.higher grade of concentrate and an improved recovery.

Fig. 2 of the drawings illustrates an arrangement of complete apparatus for carrying out this invention in the form of a flow sheet with the parts correspondingly lettered, additionally showing a storage tank k and a flotation machine treceiving the stored oily liquid from the storage tank 70 and a flotation machine a receiving the gaseous material exhausted bythe air pump 0 through the outlet pipe 2. The details of these apparatus have heretofore been sufiiciently described, and obviously the nature and arrangement of the apparatus would be varied to suit the requirements of different installations and best carry out the process constituting this invention.

I claim 1. The process of concentrating ores which consists in mixing with an ore pulp a mineral frothing agent obtained by subjecting a frothing agent. to partial decomposition in the presence of oxygen with the production of substantial amounts-of easily condensable .material other than water and also bring- .ing gaseous u b s nt contact with the machine,

presence of oxygen'with the production of substantial amounts of-easily' condensable material other than water andalso bringing gaseous bubbles into contact with tliesolid particles in the ore pulp so as toproduce mineral-bearing froth, and separating the froth.

4. The process of concentrating ores which consists in mixing with an ore pulp a mineral frothing agent obtained by subjecting a frothing agent to partial decomposition in the presence of oxygen with the production of'substantial amounts of easily'condensable material other than water and also bringing gaseous bubbles into contact with the solid particles in the ore pulp so as to produce mineral-bearing froth, and separating the froth.

5.-The' process of concentrating oreswhich consists in mixing with an ore pulp a mineral frothing agent obtained by subjecting an insoluble fr'othing' agent to a partially decomposing heat in the presence of-oxygen 1 with the production of substantial amounts of easily condensable material other than water and also-bringing gaseous bubbles into contact with the solid particles in the ore pulp so as to produce mineral-bearing froth and separating the froth.

6. The process of concentrating ores which consists in mixing with an ore pulp a product obtained by subjecting oleic acid'to a partially decomposing heat in the presence of oxygen and also bringing gaseous bubbles 8. The process of concentrating ores which consists in mixing with an ore pulp a min eral frothing agent obtained by subjecting an insolubly fatty acid-bearing substance to a partially decomposing heat in the presence of oxygen to effect substantial. oxidation thereof and also bringing gaseous bubbles into contact with the solid particles in the ore pulp so as to produce mineral-bearing froth, and separatingthe froth. V

9. The process of concentrating ores which consists in mixingwith an ore pulp an oily product obtained by subjecting oleic acid to substantial oxidation by heat in the pres ence of onygen to effect substantial oxidation fatty acid-bearing substance to a partially decomposing heat in the presence of oxygen to effect substantial oxidation thereof and also bringing gaseous bubbles into contact with the solid particles in the ore pulp so as to produce Inineral-bearingfroth, and separating the froth.

11. The process of concentrating ores which consists in mixing With an ore pulp an' oily distillate obtained by subjecting a fattytacid-bearing substance to a to effect substantial oxidation thereof and partially decomposing heat 'in'the presence of oxygen 3'5; also bringing gaseous; bubbles into contactf '2 .with the solid-particles in the ore pulptso as to produce mineral-bearing froth, and

separating the froth.. Y

12; The process of concentrating ores which consists in"m1xingwith an ore pulp an oily distillate obtained by subjecting oleic acid to partial decompositioninthe presence of oxygen and also bringing gaseous bubblesinto contact with the solid particles in the ore pulp so as to produce mineral-bearing froth, and separating the froth. In testimony whereof, I have affiXed'my signature to this specification.

ELTOFT WRAY WILKINSON. 

